1. Field of Invention
The present invention relates generally to self-wringing mops and, more particularly, to self-wringing mops that can accept a replacement cleaning element assembly and to such replacement cleaning element or mop head assemblies.
2. Description of the Related Art
Self-wringing mops, which include a replaceable sponge assembly that is movable between a cleaning, or use, position and a wringing position, are well known. The sponge assembly is typically connected to an actuator rod, which is itself connected to a lever that is manually operated by the person using the mop. When the user moves the lever away from the sponge assembly, the rod pulls the sponge assembly through a pair of rollers held by a wringer head assembly. The rollers apply pressure to the sponge to wring liquid from the sponge. The lever may then be moved in the opposite direction to return the sponge assembly to the cleaning position. One example of a conventional self-wringing sponge mop is the so-called roll-o-matic sponge mop.
The sponge assemblies employed in self-wringing sponge mops are typically composed of a sponge held by a metal clamp adapted to be connected to the actuator rod. The metal clamp holds the sponge in place and serves as an adapter which allows the sponge assembly to be connected to the mop. One example of a sponge assembly is illustrated in U.S. Pat. No. 4,908,901, which issued in 1990 to Torres.
There are a number of disadvantages associated with conventional self-wringing sponge mops in general, and with conventional sponges, sponge assemblies, and wringer head assemblies in particular.
Turning first to the sponge assemblies, many of the disadvantages associated with conventional sponge assemblies derive from the metal clamp which holds the sponge. The clamp covers and holds a significant portion of the sponge. The covered and clamped portion of the sponge is not affected by the squeezing force applied by the rollers. As such, bacteria, dirt and other contaminants can become trapped within this portion of the sponge, as can moisture, which leads to the growth of mildew. The clamps also include sharp edges which can scratch persons using the mop, the surfaces being mopped and items on or adjacent to these surfaces and possibly produce other contaminants such as particulates. Other shortcomings of conventional sponge assemblies relate to the fact that the clamp is permanently affixed to the sponge and is discarded with the sponge when the sponge is worn out. Not only is it wasteful to throw away a clamp which is not itself worn out, but the clamp cannot be compressed and adds significant weight and volume to the material which is to be disposed of Thus, disposal of conventional sponge assemblies can be especially expensive in situations where the sponge mop is being used in conjunction with hazardous substances that cannot be disposed of by conventional techniques. Finally, as the clamp must be manufactured and attached to the sponge, it adds a significant amount to the cost of the sponge assembly.
Another disadvantage associated with conventional sponge assemblies is related to covers which are sometimes used to cover the sponge. Covers are often composed of material such as polyvinyl alcohol (PVA) and provide a relatively non-linting, smooth and absorbent cleaning surface. However, due to the manner in which sponges are attached to conventional clamps, the cover separates from the sponge as the sponge passes through the rollers. This prevents the rollers from wringing liquid, dirt and other contaminants from the cover.
The shape of the sponge used in conventional sponge assemblies can also be improved. For example, the portion of the sponge's total surface area that is actually available for scrubbing or wiping is limited. In addition, the side portions of the sponge tend to be narrow and not well adapted for scrubbing. As such, conventional sponge assemblies do not make efficient use of the sponge's potentially available scrubbing surface and cannot be as easily used to clean walls and other vertically extending surfaces as desired.
With respect to the self-wringing sponge mops themselves, a significant amount of force must be applied to the lever in order to pull the sponge through the rollers and wring liquid from the sponge. A similar amount of force must be applied to return the sponge to the use position. Accordingly, use of conventional self-wringing sponge mops over prolonged periods can be quite fatiguing. Moreover, the amount of force required to operate the lever is often greater than that which can be generated by persons of somewhat limited physical capabilities, such as those afflicted with disabilities.
The wringer head assembly of conventional self-wringing sponge mops can also be troublesome. For example, the ends of the roller mounting rods often become exposed and can scratch persons using the mop, the surfaces being mopped, and items on or adjacent to these surfaces. In addition, bacteria, dirt and other contaminants often enter the mop's tubular handle at the point of connection between the handle and the wringer head assembly. Such contaminants can escape during subsequent uses of the mop. Conventional wringer head assemblies also tend to be formed from two pressed pieces of sheet metal. Each piece supports a single roller. Such an arrangement makes it particularly difficult to control the amount of assembly flexing during wringing processes. In addition, such assemblies are riveted to the mop handle, thereby reducing the flexibility of the mop and making it difficult to replace a damaged assembly. The configuration of conventional wringer head assemblies also makes it difficult to replace the sponge assembly.
Accordingly, a need exists for a sponge assembly having both an improved sponge holding apparatus and a more efficient sponge design. A need also exists for a self-wringing sponge mop which does not require the person using the mop to manually apply a significant amount of force to drive the sponge from the use position, through the rollers, and then back again. There is also a need for a roller assembly which is less likely to cause scratching and allow contaminants into the mop's handle, and which is capable of controlled flexing and easy replacement.